Effect Of Different Process Parameters Research Articles

Characterization and Multiscale Modeling of the Mechanical Properties for FDM-Printed Copper-Reinforced PLA Composites.

Additive manufacturing is an emerging technology and provides high design flexibility to customers. Fused deposition modeling (FDM) is an economical and promising additive manufacturing method. Due to its many advantages, FDM received great attention in recent years, and comprehensive studies are being undertaken to investigate the properties of FDM-printed polymers and polymer composites. As a result of the manufacturing technology employed in FDM, inner structures are changed with different process parameters, and thus, anisotropic properties are observed. Moreover, composite filaments such as particle- or fiber-reinforced polymers already have anisotropy before FDM printing. In this study, we investigate the effect of different process parameters, namely layer thickness and raster width on FDM-printed copper-reinforced poly(lactic acid) (PLA). Mechanical characterizations with a high-resolution camera are carried out for analyzing the deformation behaviors. Optical microscopy characterizations are performed to observe the mesostructural changes with various process parameters. Scanning electron microscopy (SEM) and an energy-dispersive X-ray spectroscopy (EDS) analysis are conducted for investigating the microstructure, specifically, copper particles in the PLA matrix. A 2D digital image correlation code with a machine learning algorithm is applied to the optical characterization and SEM-EDS images. In this way, micro- and mesostructural features, as well as the porosity ratios of the specimens are investigated. We prepare the multiscale homogenization by finite element method (FEM) simulations to capture the material’s response, both on a microscale and a mesoscale. We determined that the mesostructure and, thereby, the mechanical properties are significantly changed with the aforementioned process parameters. A lower layer thickness and a greater raster width led to a higher elasticity modulus and ultimate tensile strength (UTS). The optical microscopy analysis verified this statement: Decreasing the layer thickness and increasing the raster width result in larger contact lines between adjacent layers and, hence, lower porosity on the mesoscale. Realistic CAD images were prepared regarding the mesostructural differences and porosity ratios. Ultimately, all these changes are accurately modeled with mesoscale and multiscale simulations. The simulation results are validated by laboratory experiments.

Precipitation hardening stainless steel samples processed by additive manufacturing: Process parameters and thermo mechanical treatments effects on microstructure and corrosion resistance

The effects of different process parameters and thermo mechanical treatments on 17–4 PH samples processed by Selective Laser Melting have been investigated in this study. Overlap, scanning radius and laser beam defocusing were varied while all the other process parameters were kept constant. So, the role of process parameters was analysed in terms of microstructure, defectiveness and response to heat treatment. Specifically, the as built samples were subjected to stress relaxation heat treatment (650 °C-2 h) and H 900 heat treatment (solution treatment at 1100 °C 1 h + 480 °C-1 h). On the as built, stress relieved and H 900 heat treated samples the corrosion resistance, microstructural evolution and hardness were studied. Moreover, Ultrasonic Peening treatment (UPT) was applied and its effect corrosion resistance was evaluated. The study was carried out by optical, scanning and transmission electron microscopes, Vickers hardness, DRX and Image analysis software. It was found that the amount of austenitic phase increases with the decreasing of the scanning radius from 5000 µm to 1250 µm; with positive defocusing of laser beam (+1mm) respect to in focus processed sample and with increasing of the overlap from 25 µm to 50 µm.Each samples exhibit pores lower than 0,3% in terms of area percentage and mostly circular in morphology. In the process variability window, no significant difference in defects occurrence were observed. In the as built state, different values of hardness were found according to the different microstructure and average grain size. After the stress relaxation heat treatments at 650 °C-2 h all the samples exhibit similar hardness values while the most austenitic and finer grained as built samples exhibit higher increasing in hardness after H900 heat treatment. Corrosion resistance changes as function of the different process parameter and heat treatment and is improved by Ultrasonic Peening mechanical treatment.

Effect of processing parameters and heat treatment techniques on foaming properties of aluminium foam developed by friction stir processing route

In the present research friction stir processing has been used to make the precursors. The substrate contains the foamable mixture in a pre-drilled hole and the processing has been done in the centre line of the hole. The developed precursors are then treated by two heating methods, i.e. furnace and microwave heating to produce foam. The effect of different process parameters like the number of friction stir processing passes, volume and composition of foamable mixture, and heat treatment techniques have been investigated. The porous aluminium foam has been found with pore size in the range of 0.24–1.35 mm with a proportion of pores between 41% and 56% with microwave heating, while in case of furnace heating, the pore size is in the range of 0.22–1.49 mm with proportion of pores in between 41% and 61%. Also, the results show that the foam developed in microwave heating is much faster than that of furnace heating.

Impact energy absorption and fracture mechanism of FFF made fiberglass reinforced polymer composites

PurposeThe fiber reinforced polymer composites are becoming more critical because of their exceptional mechanical properties and lightweight structures. Fused filament fabrication (FFF) is a three-dimensional (3D) printing technique that can manufacture composite structures. However, the effect of impact performance on the structural integrity of FFF made composites compared to the pre-preg composites is a primary concern for the practical usage of 3D printed parts. Therefore, this paper aims to investigate the effect of different processing parameters on the impact performance of 3D printed composites.Design/methodology/approachThis paper investigates the impact of build orientation, fiber stacking sequence and fiber angle on the impact properties. Two build orientations, three fiber stacking sequences and two different fiber angles have been selected for this study. Charpy impact testing is carried out to investigate the impact energy absorption of the parts. Onyx as a matrix material and two different types of fibers, that is, fiberglass and high strength high temperature (HSHT) fiberglass as reinforcements, are used for the fabrication.FindingsResults indicate that build orientation and fiber angle largely affect the impact performance of composite parts. The composite part built with XYZ orientation, 0º/90º fiber angle and B type fiber stacking sequence resulted into maximum impact energy. However, comparing both types of fiber reinforcement, HSHT fiberglass resulted in higher impact energy than regular fiberglass.Originality/valueThis study evaluates the damage modes during the impact testing of the 3D printed composite parts. The impact energy absorbed by the composite samples during the impact testing is measured to compare the effect of different processing conditions. The investigation of different types of fiberglass reinforced with Onyx material is very limited for the FFF-based process. The results also provide a database to select the different parameters to obtain the required impact properties.

Growth and application of MoSe2 in solar cells

MoSe2 from monolayer to bulk phase can realize the transition from a direct bandgap semiconductor to an indirect bandgap semiconductor. Its bandgap varies between 1.1 and 1.55 eV, which matches the solar spectral range, so Si-based heterojunction solar cells with MoSe2 as an active layer have great significance in the development of low-cost, high-efficiency and high-flexibility photovoltaic devices. In this work, MoSe2 thin films were synthesized by chemical vapor deposition using MoO3 and Se powders as precursor sources. The effects of different process parameters (Se source temperature, Mo source temperature, growth time, carrier gas flow rate and hydrogen ratio) on the synthesis of MoSe2 thin films were systematically investigated. The optimized experimental parameters were determined as follows: the molybdenum source temperature of 800[Formula: see text], the selenium source 20 cm away from molybdenum source, the growth time of 10 min, the carrier gas flow rate of 60 sccm, the hydrogen ratio of 10%. Then MoSe2/Si heterojunction solar cells were constructed via wet chemical transfer. The open-circuit voltage, short-circuit current density, filling factor and photovoltaic conversion efficiency of the fabricated solar cells were 0.19 V, 5.71 mA/cm2, 30.47% and 0.33%, respectively. Main factors affecting the photovoltaic performance of the MoSe2/Si solar cells have also been discussed. This work is very helpful for the development of MoSe2 material and relevant application in the field of solar cells.

A VFM-based identification method for the dynamic anisotropic plasticity of sheet metals

The anisotropic plasticity of sheet metals at high strain rates is a critical factor that can influence the fabrication and service safety of engineering parts under dynamic loading conditions. The characterization of dynamic anisotropic plasticity using conventional testing methods usually suffers from the limitations resulted from the homogeneous deformation state and one-dimensional wave propagation preconditions. In this work, a highly efficient approach is proposed for the simultaneous identification of the anisotropic yielding and hardening constitutive parameters at high strain rates based on the heterogeneous impact test and the virtual fields method. First, the identification framework that combines the selected anisotropic plasticity constitutive models and the principle of virtual work concerning the dynamic kinematics term is introduced. In order to validate the proposed identification algorithm, simulated virtual impact tests were performed to provide reference parameters and unpolluted inertial acceleration/strain/strain rate field data. These data were then processed to extract the target dynamic anisotropic parameters. The results show that using the double-notched impact configuration and the proposed identification algorithm the selected anisotropic yielding and hardening parameters can be reasonably identified from a single impact test, significantly simplifying the testing procedures compared to conventional dynamic testing methods. Also, the effects of different processing parameters and influential factors on the identification accuracy have been investigated. From the sensitivity studies, the preferred ranges of the processing parameters have been determined and the robustness of the proposed method within these verified.

Effect of process parameters on porosity defects in Al-Si alloy hot rolling

Hot-rolled Al-Si alloy sheets are used to be formed Al alloy welding additions and cladding materials that are widely used in the aviation, automotive, and air conditioning industries. However, if parameters of hot-rolling process are not properly selected, porosity defects during casting will lead to cracks or fractures in Al-Si alloy sheets. This study based on meso-damage theory and established a damage equation describing porosity defects in the hot rolling process. The parameters of GTN (Gurson-Tvergaard-Needleman) void defect evolution, including the volume fraction of voids in different periods, the plastic equivalent variation of void nucleation, the standard variance of equivalent variation of void nucleation, and the correction coefficient of the material, are determined in this study. A finite element model of the porosity defects is developed based on the determined parameters. The finite element method is used to analyze the effect of different process parameters on the porosity defects and cracks in Al-Si alloy sheets during hot rolling, then we performed the hot rolling test to validate the results. The results show that the void stress and diameter are reduced and the quality of porosity defects is improved by decreasing rolling reductions and increasing the temperature. The optimized process parameters were a 20% depression and a temperature of 550°C.

Influence of process parameters on mechanical strength, build time, and material consumption of 3D printed polylactic acid parts

AbstractThe purpose of the study is to examine and analyze the effect of different process parameters of fused deposition modeling process, namely, nozzle diameter, build orientation, infill density, raster pattern, layer height, and print speed on the response variables, namely, tensile strength, build time, and material consumption. Taguchi L27 orthogonal array experimental design has been adopted to print the PLA samples for experimental investigation. The optimum values of process parameters are obtained from the signal‐to‐noise ratio values of responses. The performed confirmation tests revealed that optimum process parameters combination determined through Taguchi method improves the tensile strength, reduce the build time, and material consumption significantly. Confirmation from analysis of variance (ANOVA) results revealed that the build orientation and nozzle diameter are the most influential process parameters for all the considered responses. The infill density is found to be an influential process parameter for material consumption. Further, the developed regression models for prediction of response characteristics and normal probability plots show significance of coefficients for predicted models. Results from the confirmation test revealed that the PLA part printed with optimum settings ((Nd)3‐(Bo)3‐(Id)3‐(Rp)1‐(Lh)2‐(Ps)1)) for tensile strength shows maximum tensile strength of 61.24 MPa with an improvement of 6.26%. Similarly, the part printed with the optimum settings ((Nd)3‐(Bo)1‐(Id)2‐(Rp)1‐(Lh)3‐(Ps)3) for build time takes 0.32 h of time with a reduction of 8.57%. The part printed with the optimum settings ((Nd)1‐(Bo)1‐(Id)1‐(Rp)2‐(Lh)1‐(Ps)2) for material consumption consumes material of 7.6 g with a reduction of 2.56%. Fracture mechanics results depict that variation of process parameters during the fabrication of samples has significant influence on the tensile strength.

Fabrication of microtexture by pulse laser to improve the bonding strength of coating

ObjectiveIn order to improve the bonding strength between Zirconia (ZrO2) coating and SUS304 stainless steel through the machined surface texture. MethodsSUS304 stainless steel was processed by nanosecond pulse laser. Based on the analysis of the orthogonal test results and the summary of the law, the primary effects of different processing parameters on the processing size were judged according to the extreme difference. Nanosecond pulse laser was used to process the textures with different shape and coverage on the surface of materials. ZrO2 coatings were made by plasma spraying technology. ResultThe tensile test results show that square and triangular textures are easy to cause stress concentration, resulting in the decrease of coating adhesion. The stress concentration of circular texture is less, the adhesion between ZrO2 coating and SUS304 substrate is stronger. It is also found that the greater the texture coverage, the stronger the adhesion between ZrO2 coating and substrate, the coatings are less likely to fall off. The texture increases the contact area, so that the interlocking structures are formed between ZrO2 coating and SUS304.

UV/TiO2/periodate system for the degradation of organic pollutants – Kinetics, mechanisms and toxicity study

In this study, the removal of refractory organic pollutants by the UV/TiO2/periodate system and the effects of different process parameters are investigated. The UV/TiO2/periodate system proves good efficient for the degradation of various recalcitrant organic pollutants, including Rhodamine B (RhB), 17α-ethynylestradiol (EE2), diclofenac (DFC), sulfamethoxazole (SMX), ciprofloxacin (CIP) and carbamazepine (CBZ). The combined UV/TiO2/periodate (IO4-) system demonstrates an improved pollutant removal efficiency (93% in 30 min) in comparison with UV/TiO2, UV/IO4-, UV/TiO2/IO3- and UV/TiO2/ClO4- processes. Scavenging experiments to identify the involved degradation mechanisms reveal the contribution of O2− > h+ > IO3∙ and IO4∙ > O(3P) >∙OH in the UV/TiO2/periodate process. Ultra-high performance liquid chromatography in combination with high-resolution mass spectrometry (UHPLC-QTOF-MS) is employed to explore the degradation products. The performance of the system is shown to be independent of pH and flexible in dealing with a wide range of effluents. The system also shows a high efficiency towards the removal of pollutants from real wastewater samples (88% at 150 min). Respirometric analyses show that the water treated with the UV/TiO2/periodate system is not toxic to microorganisms in activated sludge. In addition to the superior treatment efficiency, the UV/TiO2/periodate system exhibits a lower treatment cost compared to both UV/TiO2/IO3- and UV/TiO2/ClO4- systems, which can potentially promote its application for real wastewater treatment.

A multifunctional composite membrane with photocatalytic, self-cleaning, oil/water separation and antibacterial properties

Multifunctional composite materials have attracted wide attention because they can be applied in many fields, and have great potential for application. The superhydrophobic surface has been favored by scientists in recent years because of its excellent properties. In this paper, carbon fabric (CF) with high porosity, good electrical conductivity and excellent flexibility was selected as substrate. The CF/Zr–TiO2/PDMS composites were prepared by solvo-thermal method on CF and modified by PDMS, which can be used in the fields of self-cleaning, self-healing, oil/water separation, antibacterial, anti-icing and so on. Furthermore, the PDMS modification has no or negligible adverse effect on the important textile physical properties of the CF. The effects of different process parameters on the structure and properties of CF/Zr–TiO2 were studied, and the samples with the best conditions were obtained. The results show that the sample achieves the transformation from superhydrophilic to superhydrophobic after modification. The CF/Zr–TiO2/PDMS composite structure not only shows excellent photocatalytic activity, but also has a certain self-cleaning ability. The samples before and after modification can separate light oil/water and heavy oil/water respectively. Compared with CF/Zr–TiO2, CF/Zr–TiO2/PDMS has better anti-Escherichia coli ability.

Rice straw biochar for removal of phenol from water

Phenols are considered as persistent organic pollutants. These are highly dangerous for human beings due to their toxic and mutagenic outcomes. Adsorption is considered as one of the most profitable method for removal of pollutants from aqueous medium. Adsorptive behavior of phenol from aqueous medium using rice straw biochar was examined. The rice straw biochar was characterized using Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy and Fourier transform Infra-red Spectroscopy. The effect of different process parameters, namely initial phenol concentration and contact time were examined. The micro porous structure on rice straw supported the absorption. About 70% of phenol was removed 60 minutes.

Research and Optimization of Process Parameters for Internal Thread Forming Based on Numerical Simulation and Experimental Analysis.

In order to improve the forming quality of extruded thread, finite element analysis and experimental research are combined to reduce the two keys that affect thread quality in the machining process—extrusion torque and extrusion temperature. The effects of different processing parameters on the extrusion torque and temperature are obtained by numerical simulation, including the bottom hole diameter of the workpiece, the machine tool speed, and the lubrication medium. For the purpose of reducing extrusion torque and temperature, the process parameters for internal thread forming are further optimized by orthogonal design. It is determined that when machining the M22 × 2 internal thread on the connecting rod of the marine diesel engine made of 42CrMo4 steel, the bottom hole diameter of the workpiece should be ∅21.20 mm, the speed of the machine tool should be 40 RPM, and the lubricating medium should be PDMS polydimethylsiloxane coolant. Compared to before optimization, the maximum extrusion torque and the maximum extrusion temperature are reduced by 19.27% and 15.07%, respectively. On the premise of ensuring the thread connection strength, the height of the thread tooth is reduced by 0.052 mm, and the surface condition of the thread is improved. The surface microhardness at the root, top, and side of the thread increases by about 5 HV0.2, and the depth of the hardened layer increases by 0.05 mm. The results show that the quality of the optimized thread is higher.

Combining the Finite Element Analysis and Kriging Model for Study on Laser Surface Hardening Parameters of Pitch Bearing Raceway.

Laser surface hardening is used to improve the fatigue performance of the large diameter pitch bearing. Determination of the process parameters by a trial and error method, depending on the experience of the technician, by changing the parameters repeatedly for each laser surface hardening process is time-consuming and costly. In this paper, a method of analyzing the maximum temperature and depth of a hardened layer during the laser surface hardening process for a pitch bearing raceway of a wind turbine is proposed, which combines finite element simulation and the Kriging model. A three-dimensional finite element model of a pitch bearing ring was established using ABAQUS. The temperature field analysis was performed. The effects of process parameters including laser power, scanning speed, and laser spot radius on the depth of the hardening layer were investigated. Then, taking into account the interactional effects of different process parameters, Kriging models were constructed to reflect the relationship between input process parameters and output responses. The results show that the Kriging approximation model has a small relative error compared with the simulated results and can be used to predict the hardened layer depth.

Multi-scale simulation of microstructure evolution during direct laser deposition of Inconel718

As a free forming additive manufacturing technology for high performance metal parts, laser deposition manufacturing has a broad application prospect in aerospace and other fields. The solidification behavior and microstructure of molten pool determine the mechanical properties of the deposited parts. A multi-scale Cellular Automaton (CA)- Finite Element (FE) model is developed to simulate the microstructure evolution with different process parameters during the Direct Laser Deposition (DLD) process. Temperature data and solidification parameters under different process parameters are obtained by finite element method, which establish connections between macroscopic temperature field and microstructure simulation. In addition, the effects of different process parameters on dendrite morphology, element segregation and grain structure are investigated. The primary dendrite arm spacing (PDAS), Nb element precipitation and grain size all increase with the increase of laser power, which are caused by the decrease of cooling rate. Moreover, the trend of the simulated results of microstructure under various process parameters are consistent with the experimental results.

Investigation of The Effects of Processing Parameters on Measuring Accuracy in Electro Erosion Machining of Ti-6Al-4V Alloy

Titanium alloys are one of the materials that are difficult to process due to their high strength, high hardness and low thermal conductivity, wherefore low tool life and surface quality and high energy consumption are involved in shaping them with traditional manufacturing methods. In particular, special tool geometries are required for the machining of complex geometry parts including helical groove, keyseat, micro-holes, etc. with traditional manufacturing methods, which leads to increases in machining costs. In such cases, non-traditional alternative processing methods are preferred. In this study, keyseat shaping procedures were performed according to DIN 6885 standard in the electro (die-sinking) erosion machine for Ti-4Al-6V alloy. As a result of experiments conducted in copper electrode and Belone EDM F dielectric fluid environment, the effects of different processing parameters (discharge current, pulse on time and pulse off time) on measuring accuracy were investigated. In addition, the effects of 3D surface and SEM images and processing parameters on the accuracy of the coordinate measurement were evaluated. With the low discharge current, less thermal energy is transferred to the workpiece and smaller particles are removed from the workpiece, obtained in closer results to the targeted values. The biggest difference between the targeted keyseat depth, width and length and the measured value was 18.13%, 4.24% and 0.625%, respectively. The results closest to the specified standard keyseat dimensions were obtained in Ip=9A, Ton=150μs, Toff=120μs processing parameters.

Effects of papain concentration, coagulation temperature, and coagulation time on the properties of model soft cheese during ripening

Cheese is a nutritious food that is a good source of bioactive compounds. Therefore, it is important to understand the effects of different processing parameters on cheese properties during the ripening process. Here, we prepared model soft cheeses by using different concentrations of papain (0.2, 0.3, and 0.4%), coagulation temperatures (30, 34, and 37 °C), and coagulation times (20, 30, and 40 min) to evaluate changes in yield, moisture content, pH, lactic acid bacteria population, texture, proteolysis, volatile compounds, and instrumental sensory analysis during a 50 days ripening period. The moisture contents were 53%–62%, and moisture-adjusted yields ranged from 11.2 kg to 15.6 kg per 100 kg milk. Moreover, during the ripening period, the number of lactic acid bacteria increased by approximately 0.5 log CFU/g. A significant increase in the total concentration of free amino acids in response to increases in papain concentration and coagulation temperature was observed. Coagulation temperature was also found to have a significant effect on the hardness and springiness of cheese. In addition, we detected 34 volatile compounds in the model soft cheeses. This study contributes to advancing our current understanding on the quality changes of model soft cheese using papain as a substitute for rennet.

Specific energy absorption during compression testing of ABS and FPU parts fabricated using LCD-SLA based 3D printer

PurposeLiquid crystal display (LCD)-based stereolithography (SLA) technique has been used in drug delivery and fabrication of microfluidic devices and piezoelectric materials. It is an additive manufacturing technique where an LCD source has been used as a mask to project the image onto the tank filled with photo curable resin. This resin, when interacted with light, becomes solid. However, critical information regarding the energy absorption during the compression analysis of different components three-dimensional (3D) printed by SLA process is still limited. Therefore, this study aims to investigate the effect of different process parameters on the compressive properties.Design/methodology/approachIn the present study, the influence of layer thickness, infill density and build orientation on the compression properties is investigated. Four infill densities, that is, 20%, 40%, 60% and 80%; five-layer thicknesses, that is, 50 µm, 75 µm, 100 µm, 150 µm and 200 µm; and two different orientations, that is, YXZ and ZXY, have been selected for this study.FindingsIt is observed that the samples printed with acrylonitrile butadiene styrene (ABS) absorbed higher energy than the flexible polyurethane (FPU). Higher infill density and sample oriented on ZXY absorbed higher energy than sample printed on YXZ orientation, in both the ABS and FPU materials. Parts printed with 80% infill density and 200 µm layer thickness resulted into maximum energy for both the materials.Originality/valueIn this study, two different types of materials are used for the compression analysis using LCD-SLA-based 3D printer. Specific energy absorbed by the samples during compression testing is measured to compare the influence of parameters. The investigation of infill parameters particularly the infill density is very limited for the SLA-based 3D printing process. Also, the results of this study provide a database to select the print parameters to obtain the required properties. The results also compare the specific energy for hard and flexible material for the same combination of the process parameters.

Impact behaviour of dissimilar AA2024-T351/7075-T651 FSWed butt-joints: effects of Al2O3-SiC particles addition

Dissimilar friction stir welding joints are widely employed in the industrial field due to the excellent microstructural and mechanical properties of the resulting joints. Nevertheless, to further enhance the weld properties, the addition of reinforcement particles on the joint-line during the process has been proven effective for increasing its mechanical performance. In the present investigation, the microstructure and the impact behaviour of FSWed joints between AA2024-T351 and AA7075-T651 aluminium plates were investigated, considering the effect of different process parameters selected through a full factorial 2k design of experiments: both the rotational and translational speed of the tool, as well as the addition of Al2O3-SiC microparticles, were considered as input parameters. Unnotched 10 x 5 x 55 mm impact specimens were tested through an instrumented 50 J Charpy pendulum: total impact energy, the two complementary initiation and propagation energies as well as the peak force were correlated to the adopted process parameters. From the performed analyses, it was found that joints with reinforcing particles are prone to form wormhole defects across the stir zone that not only affect the microstructural development, but also the impact behaviour since they require less energy at break in comparison with joints fabricated without particles addition.

Effect of Different Process Parameters and Ultrasonic Treatment During Solid Osmotic Dehydration of Jasmine for Extraction of Flavoured Syrup on the Mass Transfer Kinetics and Quality Attributes

Effect of Different Process Parameters and Ultrasonic Treatment During Solid Osmotic Dehydration of Jasmine for Extraction of Flavoured Syrup on the Mass Transfer Kinetics and Quality Attributes